1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Sensirion SHT3x-DIS humidity and temperature sensor driver. 3 * The SHT3x comes in many different versions, this driver is for the 4 * I2C version only. 5 * 6 * Copyright (C) 2016 Sensirion AG, Switzerland 7 * Author: David Frey <david.frey@sensirion.com> 8 * Author: Pascal Sachs <pascal.sachs@sensirion.com> 9 */ 10 11 #include <asm/page.h> 12 #include <linux/crc8.h> 13 #include <linux/debugfs.h> 14 #include <linux/delay.h> 15 #include <linux/err.h> 16 #include <linux/hwmon.h> 17 #include <linux/hwmon-sysfs.h> 18 #include <linux/i2c.h> 19 #include <linux/init.h> 20 #include <linux/kernel.h> 21 #include <linux/module.h> 22 #include <linux/slab.h> 23 #include <linux/jiffies.h> 24 25 /* commands (high repeatability mode) */ 26 static const unsigned char sht3x_cmd_measure_single_hpm[] = { 0x24, 0x00 }; 27 28 /* commands (medium repeatability mode) */ 29 static const unsigned char sht3x_cmd_measure_single_mpm[] = { 0x24, 0x0b }; 30 31 /* commands (low repeatability mode) */ 32 static const unsigned char sht3x_cmd_measure_single_lpm[] = { 0x24, 0x16 }; 33 34 /* commands for periodic mode */ 35 static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 }; 36 static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 }; 37 38 /* commands for heater control */ 39 static const unsigned char sht3x_cmd_heater_on[] = { 0x30, 0x6d }; 40 static const unsigned char sht3x_cmd_heater_off[] = { 0x30, 0x66 }; 41 42 /* other commands */ 43 static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d }; 44 static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 }; 45 static const unsigned char sht3x_cmd_read_serial_number[] = { 0x37, 0x80 }; 46 47 /* delays for single-shot mode i2c commands, both in us */ 48 #define SHT3X_SINGLE_WAIT_TIME_HPM 15000 49 #define SHT3X_SINGLE_WAIT_TIME_MPM 6000 50 #define SHT3X_SINGLE_WAIT_TIME_LPM 4000 51 52 #define SHT3X_WORD_LEN 2 53 #define SHT3X_CMD_LENGTH 2 54 #define SHT3X_CRC8_LEN 1 55 #define SHT3X_RESPONSE_LENGTH 6 56 #define SHT3X_CRC8_POLYNOMIAL 0x31 57 #define SHT3X_CRC8_INIT 0xFF 58 #define SHT3X_MIN_TEMPERATURE -45000 59 #define SHT3X_MAX_TEMPERATURE 130000 60 #define SHT3X_MIN_HUMIDITY 0 61 #define SHT3X_MAX_HUMIDITY 100000 62 63 enum sht3x_chips { 64 sht3x, 65 sts3x, 66 }; 67 68 enum sht3x_limits { 69 limit_max = 0, 70 limit_max_hyst, 71 limit_min, 72 limit_min_hyst, 73 }; 74 75 enum sht3x_repeatability { 76 low_repeatability, 77 medium_repeatability, 78 high_repeatability, 79 }; 80 81 DECLARE_CRC8_TABLE(sht3x_crc8_table); 82 83 /* periodic measure commands (high repeatability mode) */ 84 static const char periodic_measure_commands_hpm[][SHT3X_CMD_LENGTH] = { 85 /* 0.5 measurements per second */ 86 {0x20, 0x32}, 87 /* 1 measurements per second */ 88 {0x21, 0x30}, 89 /* 2 measurements per second */ 90 {0x22, 0x36}, 91 /* 4 measurements per second */ 92 {0x23, 0x34}, 93 /* 10 measurements per second */ 94 {0x27, 0x37}, 95 }; 96 97 /* periodic measure commands (medium repeatability) */ 98 static const char periodic_measure_commands_mpm[][SHT3X_CMD_LENGTH] = { 99 /* 0.5 measurements per second */ 100 {0x20, 0x24}, 101 /* 1 measurements per second */ 102 {0x21, 0x26}, 103 /* 2 measurements per second */ 104 {0x22, 0x20}, 105 /* 4 measurements per second */ 106 {0x23, 0x22}, 107 /* 10 measurements per second */ 108 {0x27, 0x21}, 109 }; 110 111 /* periodic measure commands (low repeatability mode) */ 112 static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = { 113 /* 0.5 measurements per second */ 114 {0x20, 0x2f}, 115 /* 1 measurements per second */ 116 {0x21, 0x2d}, 117 /* 2 measurements per second */ 118 {0x22, 0x2b}, 119 /* 4 measurements per second */ 120 {0x23, 0x29}, 121 /* 10 measurements per second */ 122 {0x27, 0x2a}, 123 }; 124 125 struct sht3x_limit_commands { 126 const char read_command[SHT3X_CMD_LENGTH]; 127 const char write_command[SHT3X_CMD_LENGTH]; 128 }; 129 130 static const struct sht3x_limit_commands limit_commands[] = { 131 /* temp1_max, humidity1_max */ 132 [limit_max] = { {0xe1, 0x1f}, {0x61, 0x1d} }, 133 /* temp_1_max_hyst, humidity1_max_hyst */ 134 [limit_max_hyst] = { {0xe1, 0x14}, {0x61, 0x16} }, 135 /* temp1_min, humidity1_min */ 136 [limit_min] = { {0xe1, 0x02}, {0x61, 0x00} }, 137 /* temp_1_min_hyst, humidity1_min_hyst */ 138 [limit_min_hyst] = { {0xe1, 0x09}, {0x61, 0x0B} }, 139 }; 140 141 #define SHT3X_NUM_LIMIT_CMD ARRAY_SIZE(limit_commands) 142 143 static const u16 mode_to_update_interval[] = { 144 0, 145 2000, 146 1000, 147 500, 148 250, 149 100, 150 }; 151 152 static const struct hwmon_channel_info * const sht3x_channel_info[] = { 153 HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL), 154 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN | 155 HWMON_T_MIN_HYST | HWMON_T_MAX | 156 HWMON_T_MAX_HYST | HWMON_T_ALARM), 157 HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN | 158 HWMON_H_MIN_HYST | HWMON_H_MAX | 159 HWMON_H_MAX_HYST | HWMON_H_ALARM), 160 NULL, 161 }; 162 163 struct sht3x_data { 164 struct i2c_client *client; 165 enum sht3x_chips chip_id; 166 struct mutex i2c_lock; /* lock for sending i2c commands */ 167 struct mutex data_lock; /* lock for updating driver data */ 168 169 u8 mode; 170 const unsigned char *command; 171 u32 wait_time; /* in us*/ 172 unsigned long last_update; /* last update in periodic mode*/ 173 enum sht3x_repeatability repeatability; 174 u32 serial_number; 175 176 /* 177 * cached values for temperature and humidity and limits 178 * the limits arrays have the following order: 179 * max, max_hyst, min, min_hyst 180 */ 181 int temperature; 182 int temperature_limits[SHT3X_NUM_LIMIT_CMD]; 183 u32 humidity; 184 u32 humidity_limits[SHT3X_NUM_LIMIT_CMD]; 185 }; 186 187 static u8 get_mode_from_update_interval(u16 value) 188 { 189 size_t index; 190 u8 number_of_modes = ARRAY_SIZE(mode_to_update_interval); 191 192 if (value == 0) 193 return 0; 194 195 /* find next faster update interval */ 196 for (index = 1; index < number_of_modes; index++) { 197 if (mode_to_update_interval[index] <= value) 198 return index; 199 } 200 201 return number_of_modes - 1; 202 } 203 204 static int sht3x_read_from_command(struct i2c_client *client, 205 struct sht3x_data *data, 206 const char *command, 207 char *buf, int length, u32 wait_time) 208 { 209 int ret; 210 211 mutex_lock(&data->i2c_lock); 212 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH); 213 214 if (ret != SHT3X_CMD_LENGTH) { 215 ret = ret < 0 ? ret : -EIO; 216 goto out; 217 } 218 219 if (wait_time) 220 usleep_range(wait_time, wait_time + 1000); 221 222 ret = i2c_master_recv(client, buf, length); 223 if (ret != length) { 224 ret = ret < 0 ? ret : -EIO; 225 goto out; 226 } 227 228 ret = 0; 229 out: 230 mutex_unlock(&data->i2c_lock); 231 return ret; 232 } 233 234 static int sht3x_extract_temperature(u16 raw) 235 { 236 /* 237 * From datasheet: 238 * T = -45 + 175 * ST / 2^16 239 * Adapted for integer fixed point (3 digit) arithmetic. 240 */ 241 return ((21875 * (int)raw) >> 13) - 45000; 242 } 243 244 static u32 sht3x_extract_humidity(u16 raw) 245 { 246 /* 247 * From datasheet: 248 * RH = 100 * SRH / 2^16 249 * Adapted for integer fixed point (3 digit) arithmetic. 250 */ 251 return (12500 * (u32)raw) >> 13; 252 } 253 254 static struct sht3x_data *sht3x_update_client(struct device *dev) 255 { 256 struct sht3x_data *data = dev_get_drvdata(dev); 257 struct i2c_client *client = data->client; 258 u16 interval_ms = mode_to_update_interval[data->mode]; 259 unsigned long interval_jiffies = msecs_to_jiffies(interval_ms); 260 unsigned char buf[SHT3X_RESPONSE_LENGTH]; 261 u16 val; 262 int ret = 0; 263 264 mutex_lock(&data->data_lock); 265 /* 266 * Only update cached readings once per update interval in periodic 267 * mode. In single shot mode the sensor measures values on demand, so 268 * every time the sysfs interface is called, a measurement is triggered. 269 * In periodic mode however, the measurement process is handled 270 * internally by the sensor and reading out sensor values only makes 271 * sense if a new reading is available. 272 */ 273 if (time_after(jiffies, data->last_update + interval_jiffies)) { 274 ret = sht3x_read_from_command(client, data, data->command, buf, 275 sizeof(buf), data->wait_time); 276 if (ret) 277 goto out; 278 279 val = be16_to_cpup((__be16 *)buf); 280 data->temperature = sht3x_extract_temperature(val); 281 val = be16_to_cpup((__be16 *)(buf + 3)); 282 data->humidity = sht3x_extract_humidity(val); 283 data->last_update = jiffies; 284 } 285 286 out: 287 mutex_unlock(&data->data_lock); 288 if (ret) 289 return ERR_PTR(ret); 290 291 return data; 292 } 293 294 static int temp1_input_read(struct device *dev) 295 { 296 struct sht3x_data *data = sht3x_update_client(dev); 297 298 if (IS_ERR(data)) 299 return PTR_ERR(data); 300 301 return data->temperature; 302 } 303 304 static int humidity1_input_read(struct device *dev) 305 { 306 struct sht3x_data *data = sht3x_update_client(dev); 307 308 if (IS_ERR(data)) 309 return PTR_ERR(data); 310 311 return data->humidity; 312 } 313 314 /* 315 * limits_update must only be called from probe or with data_lock held 316 */ 317 static int limits_update(struct sht3x_data *data) 318 { 319 int ret; 320 u8 index; 321 int temperature; 322 u32 humidity; 323 u16 raw; 324 char buffer[SHT3X_RESPONSE_LENGTH]; 325 const struct sht3x_limit_commands *commands; 326 struct i2c_client *client = data->client; 327 328 for (index = 0; index < SHT3X_NUM_LIMIT_CMD; index++) { 329 commands = &limit_commands[index]; 330 ret = sht3x_read_from_command(client, data, 331 commands->read_command, buffer, 332 SHT3X_RESPONSE_LENGTH, 0); 333 334 if (ret) 335 return ret; 336 337 raw = be16_to_cpup((__be16 *)buffer); 338 temperature = sht3x_extract_temperature((raw & 0x01ff) << 7); 339 humidity = sht3x_extract_humidity(raw & 0xfe00); 340 data->temperature_limits[index] = temperature; 341 data->humidity_limits[index] = humidity; 342 } 343 344 return ret; 345 } 346 347 static int temp1_limit_read(struct device *dev, int index) 348 { 349 struct sht3x_data *data = dev_get_drvdata(dev); 350 351 return data->temperature_limits[index]; 352 } 353 354 static int humidity1_limit_read(struct device *dev, int index) 355 { 356 struct sht3x_data *data = dev_get_drvdata(dev); 357 358 return data->humidity_limits[index]; 359 } 360 361 /* 362 * limit_write must only be called with data_lock held 363 */ 364 static size_t limit_write(struct device *dev, 365 u8 index, 366 int temperature, 367 u32 humidity) 368 { 369 char buffer[SHT3X_CMD_LENGTH + SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 370 char *position = buffer; 371 int ret; 372 u16 raw; 373 struct sht3x_data *data = dev_get_drvdata(dev); 374 struct i2c_client *client = data->client; 375 const struct sht3x_limit_commands *commands; 376 377 commands = &limit_commands[index]; 378 379 memcpy(position, commands->write_command, SHT3X_CMD_LENGTH); 380 position += SHT3X_CMD_LENGTH; 381 /* 382 * ST = (T + 45) / 175 * 2^16 383 * SRH = RH / 100 * 2^16 384 * adapted for fixed point arithmetic and packed the same as 385 * in limit_read() 386 */ 387 raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7); 388 raw |= ((humidity * 42950) >> 16) & 0xfe00; 389 390 *((__be16 *)position) = cpu_to_be16(raw); 391 position += SHT3X_WORD_LEN; 392 *position = crc8(sht3x_crc8_table, 393 position - SHT3X_WORD_LEN, 394 SHT3X_WORD_LEN, 395 SHT3X_CRC8_INIT); 396 397 mutex_lock(&data->i2c_lock); 398 ret = i2c_master_send(client, buffer, sizeof(buffer)); 399 mutex_unlock(&data->i2c_lock); 400 401 if (ret != sizeof(buffer)) 402 return ret < 0 ? ret : -EIO; 403 404 data->temperature_limits[index] = temperature; 405 data->humidity_limits[index] = humidity; 406 407 return 0; 408 } 409 410 static int temp1_limit_write(struct device *dev, int index, int val) 411 { 412 int temperature; 413 int ret; 414 struct sht3x_data *data = dev_get_drvdata(dev); 415 416 temperature = clamp_val(val, SHT3X_MIN_TEMPERATURE, 417 SHT3X_MAX_TEMPERATURE); 418 mutex_lock(&data->data_lock); 419 ret = limit_write(dev, index, temperature, 420 data->humidity_limits[index]); 421 mutex_unlock(&data->data_lock); 422 423 return ret; 424 } 425 426 static int humidity1_limit_write(struct device *dev, int index, int val) 427 { 428 u32 humidity; 429 int ret; 430 struct sht3x_data *data = dev_get_drvdata(dev); 431 432 humidity = clamp_val(val, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY); 433 mutex_lock(&data->data_lock); 434 ret = limit_write(dev, index, data->temperature_limits[index], 435 humidity); 436 mutex_unlock(&data->data_lock); 437 438 return ret; 439 } 440 441 static void sht3x_select_command(struct sht3x_data *data) 442 { 443 /* 444 * For single-shot mode, only non blocking mode is support, 445 * we have to wait ourselves for result. 446 */ 447 if (data->mode > 0) { 448 data->command = sht3x_cmd_measure_periodic_mode; 449 data->wait_time = 0; 450 } else { 451 if (data->repeatability == high_repeatability) { 452 data->command = sht3x_cmd_measure_single_hpm; 453 data->wait_time = SHT3X_SINGLE_WAIT_TIME_HPM; 454 } else if (data->repeatability == medium_repeatability) { 455 data->command = sht3x_cmd_measure_single_mpm; 456 data->wait_time = SHT3X_SINGLE_WAIT_TIME_MPM; 457 } else { 458 data->command = sht3x_cmd_measure_single_lpm; 459 data->wait_time = SHT3X_SINGLE_WAIT_TIME_LPM; 460 } 461 } 462 } 463 464 static int status_register_read(struct device *dev, 465 char *buffer, int length) 466 { 467 int ret; 468 struct sht3x_data *data = dev_get_drvdata(dev); 469 struct i2c_client *client = data->client; 470 471 ret = sht3x_read_from_command(client, data, sht3x_cmd_read_status_reg, 472 buffer, length, 0); 473 474 return ret; 475 } 476 477 static int temp1_alarm_read(struct device *dev) 478 { 479 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 480 int ret; 481 482 ret = status_register_read(dev, buffer, 483 SHT3X_WORD_LEN + SHT3X_CRC8_LEN); 484 if (ret) 485 return ret; 486 487 return !!(buffer[0] & 0x04); 488 } 489 490 static int humidity1_alarm_read(struct device *dev) 491 { 492 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 493 int ret; 494 495 ret = status_register_read(dev, buffer, 496 SHT3X_WORD_LEN + SHT3X_CRC8_LEN); 497 if (ret) 498 return ret; 499 500 return !!(buffer[0] & 0x08); 501 } 502 503 static ssize_t heater_enable_show(struct device *dev, 504 struct device_attribute *attr, 505 char *buf) 506 { 507 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 508 int ret; 509 510 ret = status_register_read(dev, buffer, 511 SHT3X_WORD_LEN + SHT3X_CRC8_LEN); 512 if (ret) 513 return ret; 514 515 return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x20)); 516 } 517 518 static ssize_t heater_enable_store(struct device *dev, 519 struct device_attribute *attr, 520 const char *buf, 521 size_t count) 522 { 523 struct sht3x_data *data = dev_get_drvdata(dev); 524 struct i2c_client *client = data->client; 525 int ret; 526 bool status; 527 528 ret = kstrtobool(buf, &status); 529 if (ret) 530 return ret; 531 532 mutex_lock(&data->i2c_lock); 533 534 if (status) 535 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_on, 536 SHT3X_CMD_LENGTH); 537 else 538 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_off, 539 SHT3X_CMD_LENGTH); 540 541 mutex_unlock(&data->i2c_lock); 542 543 return ret; 544 } 545 546 static int update_interval_read(struct device *dev) 547 { 548 struct sht3x_data *data = dev_get_drvdata(dev); 549 550 return mode_to_update_interval[data->mode]; 551 } 552 553 static int update_interval_write(struct device *dev, int val) 554 { 555 u8 mode; 556 int ret; 557 const char *command; 558 struct sht3x_data *data = dev_get_drvdata(dev); 559 struct i2c_client *client = data->client; 560 561 mode = get_mode_from_update_interval(val); 562 563 mutex_lock(&data->data_lock); 564 /* mode did not change */ 565 if (mode == data->mode) { 566 mutex_unlock(&data->data_lock); 567 return 0; 568 } 569 570 mutex_lock(&data->i2c_lock); 571 /* 572 * Abort periodic measure mode. 573 * To do any changes to the configuration while in periodic mode, we 574 * have to send a break command to the sensor, which then falls back 575 * to single shot (mode = 0). 576 */ 577 if (data->mode > 0) { 578 ret = i2c_master_send(client, sht3x_cmd_break, 579 SHT3X_CMD_LENGTH); 580 if (ret != SHT3X_CMD_LENGTH) 581 goto out; 582 data->mode = 0; 583 } 584 585 if (mode > 0) { 586 if (data->repeatability == high_repeatability) 587 command = periodic_measure_commands_hpm[mode - 1]; 588 else if (data->repeatability == medium_repeatability) 589 command = periodic_measure_commands_mpm[mode - 1]; 590 else 591 command = periodic_measure_commands_lpm[mode - 1]; 592 593 /* select mode */ 594 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH); 595 if (ret != SHT3X_CMD_LENGTH) 596 goto out; 597 } 598 599 /* select mode and command */ 600 data->mode = mode; 601 sht3x_select_command(data); 602 603 out: 604 mutex_unlock(&data->i2c_lock); 605 mutex_unlock(&data->data_lock); 606 if (ret != SHT3X_CMD_LENGTH) 607 return ret < 0 ? ret : -EIO; 608 609 return 0; 610 } 611 612 static ssize_t repeatability_show(struct device *dev, 613 struct device_attribute *attr, 614 char *buf) 615 { 616 struct sht3x_data *data = dev_get_drvdata(dev); 617 618 return sysfs_emit(buf, "%d\n", data->repeatability); 619 } 620 621 static ssize_t repeatability_store(struct device *dev, 622 struct device_attribute *attr, 623 const char *buf, 624 size_t count) 625 { 626 int ret; 627 u8 val; 628 629 struct sht3x_data *data = dev_get_drvdata(dev); 630 631 ret = kstrtou8(buf, 0, &val); 632 if (ret) 633 return ret; 634 635 if (val > 2) 636 return -EINVAL; 637 638 data->repeatability = val; 639 640 return count; 641 } 642 643 static SENSOR_DEVICE_ATTR_RW(heater_enable, heater_enable, 0); 644 static SENSOR_DEVICE_ATTR_RW(repeatability, repeatability, 0); 645 646 static struct attribute *sht3x_attrs[] = { 647 &sensor_dev_attr_heater_enable.dev_attr.attr, 648 &sensor_dev_attr_repeatability.dev_attr.attr, 649 NULL 650 }; 651 652 ATTRIBUTE_GROUPS(sht3x); 653 654 static umode_t sht3x_is_visible(const void *data, enum hwmon_sensor_types type, 655 u32 attr, int channel) 656 { 657 const struct sht3x_data *chip_data = data; 658 659 switch (type) { 660 case hwmon_chip: 661 switch (attr) { 662 case hwmon_chip_update_interval: 663 return 0644; 664 default: 665 break; 666 } 667 break; 668 case hwmon_temp: 669 switch (attr) { 670 case hwmon_temp_input: 671 case hwmon_temp_alarm: 672 return 0444; 673 case hwmon_temp_max: 674 case hwmon_temp_max_hyst: 675 case hwmon_temp_min: 676 case hwmon_temp_min_hyst: 677 return 0644; 678 default: 679 break; 680 } 681 break; 682 case hwmon_humidity: 683 if (chip_data->chip_id == sts3x) 684 break; 685 switch (attr) { 686 case hwmon_humidity_input: 687 case hwmon_humidity_alarm: 688 return 0444; 689 case hwmon_humidity_max: 690 case hwmon_humidity_max_hyst: 691 case hwmon_humidity_min: 692 case hwmon_humidity_min_hyst: 693 return 0644; 694 default: 695 break; 696 } 697 break; 698 default: 699 break; 700 } 701 702 return 0; 703 } 704 705 static int sht3x_read(struct device *dev, enum hwmon_sensor_types type, 706 u32 attr, int channel, long *val) 707 { 708 enum sht3x_limits index; 709 710 switch (type) { 711 case hwmon_chip: 712 switch (attr) { 713 case hwmon_chip_update_interval: 714 *val = update_interval_read(dev); 715 break; 716 default: 717 return -EOPNOTSUPP; 718 } 719 break; 720 case hwmon_temp: 721 switch (attr) { 722 case hwmon_temp_input: 723 *val = temp1_input_read(dev); 724 break; 725 case hwmon_temp_alarm: 726 *val = temp1_alarm_read(dev); 727 break; 728 case hwmon_temp_max: 729 index = limit_max; 730 *val = temp1_limit_read(dev, index); 731 break; 732 case hwmon_temp_max_hyst: 733 index = limit_max_hyst; 734 *val = temp1_limit_read(dev, index); 735 break; 736 case hwmon_temp_min: 737 index = limit_min; 738 *val = temp1_limit_read(dev, index); 739 break; 740 case hwmon_temp_min_hyst: 741 index = limit_min_hyst; 742 *val = temp1_limit_read(dev, index); 743 break; 744 default: 745 return -EOPNOTSUPP; 746 } 747 break; 748 case hwmon_humidity: 749 switch (attr) { 750 case hwmon_humidity_input: 751 *val = humidity1_input_read(dev); 752 break; 753 case hwmon_humidity_alarm: 754 *val = humidity1_alarm_read(dev); 755 break; 756 case hwmon_humidity_max: 757 index = limit_max; 758 *val = humidity1_limit_read(dev, index); 759 break; 760 case hwmon_humidity_max_hyst: 761 index = limit_max_hyst; 762 *val = humidity1_limit_read(dev, index); 763 break; 764 case hwmon_humidity_min: 765 index = limit_min; 766 *val = humidity1_limit_read(dev, index); 767 break; 768 case hwmon_humidity_min_hyst: 769 index = limit_min_hyst; 770 *val = humidity1_limit_read(dev, index); 771 break; 772 default: 773 return -EOPNOTSUPP; 774 } 775 break; 776 default: 777 return -EOPNOTSUPP; 778 } 779 780 return 0; 781 } 782 783 static int sht3x_write(struct device *dev, enum hwmon_sensor_types type, 784 u32 attr, int channel, long val) 785 { 786 enum sht3x_limits index; 787 788 switch (type) { 789 case hwmon_chip: 790 switch (attr) { 791 case hwmon_chip_update_interval: 792 return update_interval_write(dev, val); 793 default: 794 return -EOPNOTSUPP; 795 } 796 case hwmon_temp: 797 switch (attr) { 798 case hwmon_temp_max: 799 index = limit_max; 800 break; 801 case hwmon_temp_max_hyst: 802 index = limit_max_hyst; 803 break; 804 case hwmon_temp_min: 805 index = limit_min; 806 break; 807 case hwmon_temp_min_hyst: 808 index = limit_min_hyst; 809 break; 810 default: 811 return -EOPNOTSUPP; 812 } 813 return temp1_limit_write(dev, index, val); 814 case hwmon_humidity: 815 switch (attr) { 816 case hwmon_humidity_max: 817 index = limit_max; 818 break; 819 case hwmon_humidity_max_hyst: 820 index = limit_max_hyst; 821 break; 822 case hwmon_humidity_min: 823 index = limit_min; 824 break; 825 case hwmon_humidity_min_hyst: 826 index = limit_min_hyst; 827 break; 828 default: 829 return -EOPNOTSUPP; 830 } 831 return humidity1_limit_write(dev, index, val); 832 default: 833 return -EOPNOTSUPP; 834 } 835 } 836 837 static void sht3x_serial_number_read(struct sht3x_data *data) 838 { 839 int ret; 840 char buffer[SHT3X_RESPONSE_LENGTH]; 841 struct i2c_client *client = data->client; 842 843 ret = sht3x_read_from_command(client, data, 844 sht3x_cmd_read_serial_number, 845 buffer, 846 SHT3X_RESPONSE_LENGTH, 0); 847 if (ret) 848 return; 849 850 data->serial_number = (buffer[0] << 24) | (buffer[1] << 16) | 851 (buffer[3] << 8) | buffer[4]; 852 853 debugfs_create_u32("serial_number", 0444, client->debugfs, &data->serial_number); 854 } 855 856 static const struct hwmon_ops sht3x_ops = { 857 .is_visible = sht3x_is_visible, 858 .read = sht3x_read, 859 .write = sht3x_write, 860 }; 861 862 static const struct hwmon_chip_info sht3x_chip_info = { 863 .ops = &sht3x_ops, 864 .info = sht3x_channel_info, 865 }; 866 867 static int sht3x_probe(struct i2c_client *client) 868 { 869 int ret; 870 struct sht3x_data *data; 871 struct device *hwmon_dev; 872 struct i2c_adapter *adap = client->adapter; 873 struct device *dev = &client->dev; 874 875 /* 876 * we require full i2c support since the sht3x uses multi-byte read and 877 * writes as well as multi-byte commands which are not supported by 878 * the smbus protocol 879 */ 880 if (!i2c_check_functionality(adap, I2C_FUNC_I2C)) 881 return -ENODEV; 882 883 ret = i2c_master_send(client, sht3x_cmd_clear_status_reg, 884 SHT3X_CMD_LENGTH); 885 if (ret != SHT3X_CMD_LENGTH) 886 return ret < 0 ? ret : -ENODEV; 887 888 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 889 if (!data) 890 return -ENOMEM; 891 892 data->repeatability = high_repeatability; 893 data->mode = 0; 894 data->last_update = jiffies - msecs_to_jiffies(3000); 895 data->client = client; 896 data->chip_id = (uintptr_t)i2c_get_match_data(client); 897 crc8_populate_msb(sht3x_crc8_table, SHT3X_CRC8_POLYNOMIAL); 898 899 sht3x_select_command(data); 900 901 mutex_init(&data->i2c_lock); 902 mutex_init(&data->data_lock); 903 904 /* 905 * An attempt to read limits register too early 906 * causes a NACK response from the chip. 907 * Waiting for an empirical delay of 500 us solves the issue. 908 */ 909 usleep_range(500, 600); 910 911 ret = limits_update(data); 912 if (ret) 913 return ret; 914 915 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, 916 &sht3x_chip_info, sht3x_groups); 917 if (IS_ERR(hwmon_dev)) 918 return PTR_ERR(hwmon_dev); 919 920 sht3x_serial_number_read(data); 921 922 return 0; 923 } 924 925 /* device ID table */ 926 static const struct i2c_device_id sht3x_ids[] = { 927 {"sht3x", sht3x}, 928 {"sts3x", sts3x}, 929 {} 930 }; 931 932 MODULE_DEVICE_TABLE(i2c, sht3x_ids); 933 934 static struct i2c_driver sht3x_i2c_driver = { 935 .driver.name = "sht3x", 936 .probe = sht3x_probe, 937 .id_table = sht3x_ids, 938 }; 939 module_i2c_driver(sht3x_i2c_driver); 940 941 MODULE_AUTHOR("David Frey <david.frey@sensirion.com>"); 942 MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>"); 943 MODULE_DESCRIPTION("Sensirion SHT3x humidity and temperature sensor driver"); 944 MODULE_LICENSE("GPL"); 945